This problem occurs because ASP.NET 2.0 sets up a file
change notification for each directory. As the number of subdirectories
increases, the numbers of file change notifications grows. Each file change
notification uses a Server Message Block (SMB) command. Because SMB commands
use system resources, the increased usage of system resources makes the
ASP.NET-based Web site or the ASP.NET-connected application appear to stop
responding.

A supported
hotfix is now available from Microsoft, but it is only intended to correct the
problem that is described in this article. Only apply it to systems that are
experiencing this specific problem. This hotfix may receive additional testing.
Therefore, if you are not severely affected by this problem, we recommend that
you wait for the next Microsoft .NET Framework 2.0 service pack that contains
this hotfix.

To resolve this problem immediately, contact Microsoft
Product Support Services to obtain the hotfix. For a complete list of Microsoft
Product Support Services telephone numbers and information about support costs,
visit the following Microsoft Web site:

Note In special cases, charges that are ordinarily incurred for
support calls may be canceled if a Microsoft Support Professional determines
that a specific update will resolve your problem. The usual support costs will
apply to additional support questions and issues that do not qualify for the
specific update in question.

Prerequisites

The .NET Framework 2.0

Restart requirement

You must restart the computer if any ASP.NET or .NET Framework
applications are running.

Hotfix replacement information

This hotfix does not replace any other software updates.

File information

The English version of this hotfix has the file
attributes (or later file attributes) that are listed in the following table.
The dates and times for these files are listed in Coordinated Universal Time
(UTC). When you view the file information, it is converted to local time. To
find the difference between UTC and local time, use the Time
Zone tab in the Date and Time tool in Control Panel.

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File name

File version

File
size

Date

Time

Platform

Aspnet_wp.exe

2.0.50727.62

23,040

21-Jan-2006

12:08

x86

System.web.dll

2.0.50727.62

5,025,792

21-Jan-2006

12:09

x86

Webengine.dll

2.0.50727.62

299,520

21-Jan-2006

12:08

x86

Registry information

To
enable this hotfix, you must add the following DWORD value at the following
registry key:

HKLM\Software\Microsoft\ASP.NET\FCNMode

If you are running a 32-bit process on an x64-based system, add the following DWORD value at the following registry key:

HKLM\SOFTWARE\Wow6432Node\Microsoft\ASP.NET\FCNMode

The following table lists possible values for the FCNMode DWORD
value and the behavior that is associated with each value.

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Value

Behavior

Does not exist

This is the default behavior. For each subdirectory, the application will create an object that will monitor the subdirectory.

0 or greater than 2

This is the default behavior.
For each subdirectory, the application will create an object that will monitor the subdirectory.

1

The application will disable File Change
Notifications (FCNs).

2

The application will create one object to monitor the main directory. The application will use this object to monitor each subdirectory.

Note Starting with the Microsoft .NET Framework 4.5 and later versions, FCNMode can be configured by using the httpRuntime settings as follows: